Light-stable pesticidal compositions

ABSTRACT

Novel light-stable pyrethrinoid pesticidal compositions comprising (a) at least one liquid vehicle, (b) at least one surface-active agent soluble in the said liquid vehicle, (c) at least one azodyestuff stabilizer selected from the group consisting of a mixture of 1-[{4-(phenylazo)-phenyl)}-azo]-3-naphthalenol and 4-[{4-(phenylazo)-phenyl}-azo]-phenol (a component of Scarlet R), 1-[4-(4-phenylazo-phenyl)-azo]-naphthalene (Red organol BS), 1-[{2-methyl-4-(2-methylphenylazo)-phenyl}-azo]-2-naphthalenol (Red Sudan IV), 1-[(2-methoxyphenol)-azo]-2-naphthaphenol (Vermillion organol); 1-[(1-naphthalenyl)-azo]-2-naphthalenol (Scarlet 2R for fat), 1-(phenylazo)-2-naphthalenol (Sudan I), 1-[(2-hydroxy-4-methyl-phenyl)-azo]-2-naphthalenol (Sudan II), 1-[{dimethyl-4-[(dimethyl)-phenyl]-azo}-phenylazo]-2-naphthalenol (Red to fat 5B), N-ethyl-1-[{4-(phenylazo)-phenyl}-azo]-2-naphthalenylamine (Red to fat 7B), 1-[{1-naphthalenyl}-azo]-2,4-benzene-diamine (Brown RR to fat), 2-[(2-methoxyphenyl)-azo]-phenol (Red to fat G), disodium 4-hydroxy-3-[(4-sulfo-1-naphthalenyl)-azo]-1-naphthalene sulfonate (azo ruby), 4-[(4-ethoxyphenyl)-azo]-1-naphthalenol (Brown to fat B), 2,4-dihydro-5-methyl-2-phenyl-4-(phenylazo)-3H-pyrazol-3-one (Yellow to fat 3G), N,N-diethyl-4-(phenylazo)-benzeneamine (Yellow to fat GGN), 2,3-dihydro-2,2-dimethyl-6-[(4-phenylazo)-1-naphthalenyl]-azo-1H-perimidine (Black to fat HB), N-[4-phenyl)-(4-phenylamino)-1-naphthalenyl]-azo methylene-2,5-cyclohexadien-1-ylidene-N-methyl-methaniminium chloride (Blue to fat B) and 1-[{4-(phenylazo)-phenyl}-azo]-2-naphthalenol and (d) at least one ester of the formula ##STR1## wherein Y is selected from the group consisting of ##STR2## in its various stereoisomeric forms and mixtures thereof, Z is alkyl of 1 to 6 carbon atoms, Y is selected from the group consisting of hydrogen, halogen, --CN, --NO 3 , alkyl of 1 to 4 carbon atoms and alkoxy of 1 to 4 carbon atoms, n is 0, 1, 2 or 3, W is selected from the group consisting of ##STR3## X 1  is selected from the group consisting of hydrogen, fluorine, chlorine and bromine, X 2  is selected from the group consisting of fluorine, chlorine and bromine, X 3  is selected from the group consisting of chlorine, bromine and iodine, X 4  is a halogen and X 5  is a halogen optionally other than that of X 4  and due to asymetric carbon atom in W, the compounds are in the A isomer or B isomer form or mixtures thereof and R is selected from the group consisting of ##STR4## and benzyl optionally substituted with at least one member of the group consisting of alkyl of 1 to 4 carbon atoms, alkenyl of 2 to 6 carbon atoms, alkenyloxy of 2 to 6 carbon atoms, alkadienyl of 4 to 8 carbon atoms, methylenedioxy, benzyl and halogens, R 1  is selected from the group consisting of hydrogen and methyl, R 2  is selected from the group consisting of monocyclic aryl and --CH 2  --C.tbd.CH, R 3  is an aliphatic of 2 to 6 carbon atoms having at least one carbon-carbon insaturation, R 4  is selected from the group consisting of hydrogen, --CN, CH 3  and --C.tbd.CH, R 5  is selected from the group consisting of chlorine and methyl, n is 0, 1 or 2, R 6 , R 7 , R 8  and R 9  are individually selected from the group consisting of hydrogen, chlorine and methyl and S/I indicates that the ring may be aromatic, dihydro or tetrahydro the alcoholic moiety R-OH being capable of containing one or more asymetric carbon atoms and of existing in the form of various stereoisomers and their use to combat pests.

STATE OF THE ART

U.S. Pat. No. 2,772,198 and French Pat. No. 2096962 describe azodyestuffstabilizer for pyrethrinoids different from these of the presentapplication.

U.S. Pat. No. 4,224,227 which is assigned to the assignee of the presentapplication describes the compounds of formula I and their use asexcellent agents for combatting pests such as insects, ticks, acariens,etc. However, it has been found that the said compounds are sensitive tolight and may decompose when subjected to sunlight under use conditions.

OBJECTS OF THE INVENTION

It is an object of the invention to provide light-stable pesiticdalcompositions containing at least one compound of formula I as the activeingredient.

It is another object of the invention to provide an improved process forcombatting pests.

These and other objects and advantages of the invention will becomeobvious from the following detailed description.

THE INVENTION

The novel light-stable pyrethrinoid compositions of the invention arecomprised of (a) at least one liquid vehicle, (b) at least onesurface-active agent soluble in the said liquid vehicle, (c) at leastone azodyestuff stabilizer selected from the group consisting of amixture of 1-[{4-(phenylazo) -phenyl)}-azo]-3-naphthalenol and4-[{4-(phenylazo)-phenyl}azo]-phenol (a component of Scarlet R),1-[4-(4-phenylazo- phenyl)-azo]-naphthalene (Red organol BS),1-[{2-methyl -4- (2-Methylphenylazo)-phenyl}-azo]-2-naphthalenol (RedSudan IV), 1-[(2-methoxyphenol)-azo]-2-naphthaphenol (Vermillionorganol); 1-[(1-naphthalenyl)-azo]-2-naphthalenol (Scarlet 2R for fat),1-(phenylazo)-2-naphthalenol (Sudan I), 1-[(2-hydroxy-4-methyl-phenyl)-azo]-2-naphthalenol (Sudan II), 1-[{dimethyl-4-[(dimethyl)phenyl]-azo}-phenylazo]-2-naphthalenol (Red to fat 5B),N-ethyl-1-[{4-(phenylazo)-phenyl}-azo]-2-naphthalenylamine (Red to fat7B), 1-[{1-naphthalenyl}-azo]-2,4-benzenediamine (Brown RR to fat),2-[(2-methoxyphenyl)-azo]-phenol (Red to fat G), disodium4-hydroxy-3-[(4-sulfo-1-naphthalenyl)-azo]-1-naphthalene sulfonate (azoruby), 4-[(4-ethoxyphenyl)-azo]-1-naphthalenol (Brown to fat B),2,4-dihydro-5-methyl-2- phenyl-4-(phenylazo)-3H-pyrazol-3-one (Yellow tofat 3G),N,N-diethyl-4-(phenylazo)-benzeneamine (Yellow to fat GGN),2,3-dihydro-2,2-dimethyl-6-[(4-phenylazo)-1-naphthalenyl]-azo-1H-perimidine(Black to fat HB),N-[4-phenyl)-(4-phenylamino)-1-naphthalenyl]-methylene-2,5-cyclohexadien-1-ylidene-N-methyl-methaniminiumchloride (Blue to fat B) and 1-/(4(phenylazo) phenyl)azo/ 2-naphtalenoland at least one ester of the formula ##STR5## wherein Y is selectedfrom the group consisting of ##STR6## in its various stereoisomericforms and mixtures thereof, Z is alkyl of 1 to 6 carbon atoms, Y isselected from the group consisting of hydrogen, halogen, --CN, --NO₃,alkyl of 1 to 4 carbon atoms and alkoxy of 1 to 4 carbon atoms, n is0,1,2, or 3, W is selected from the group consisting of ##STR7## X₁ isselected from the group consisting of hydrogen, fluorine, chlorine andbromine, X₂ is selected from the group consisting of fluorine, chlorineand bromine, X₃ is selected from the group consisting of chlorine,bromine and iodine, X₄ is a halogen and X₅ is a halogen optionally otherthan that of X₄ and due to asymetric carbon atom in W, the compounds arein the A isomer or B isomer form or mixtures thereof and R is selectedfrom the group consisting of ##STR8## and benzyl optionally substitutedwith at least one member of the group consisting of alkyl of 1 to 4carbon atoms, alkenyl of 2 to 6 carbon atoms, alkenyloxy of 2 to 6carbon atoms, alkadienyl of 4 to 8 carbon atoms, methylenedioxy, benzyland halogens, R₁ is selected from the group consisting of hydrogen andmethyl, R₂ is selected from the group consisting of monocyclic aryl and--CH₂ --C.tbd.CH, R₃ is an aliphatic of 2 to 6 carbon atoms having atleast one carbon-carbon insaturation, R₄ is selected from the groupconsisting of hydrogen, --CN, CH₃ and --C.tbd.CH, R₅ is selected fromthe group consisting of chlorine and methyl, n is O, 1 or 2, R₆, R₇, R₈and R₉ are individually selected from the group consisting of hydrogen,chlorine and methyl and S/I indicates that the ring may be aromatic,dihydro or tetrahydro the alcoholic moiety R--OH being capable ofcontaining one or more asymetric carbon atoms and of existing in theform of various stereoisomers. The compositions are preferably in theform of an emulsifable concentrate.

Among the preferred light-stable compositions of the invention are thosewherein the azodyestuff is a mixture of1-[{4-(phenylazo)-phenyl}-azo]-3-naphthalenol and 4-[{4-(phenylazo)-phenyl}-azo]-phenol (Scarlet to fat), those wherein the azodyestuff is1-[{4-(phenylazo)-phenyl}-azo]-2-naphthalenol, those wherein theazodyestuff isN-ethyl-1-[{4-(phenylazo)-phenyl}-azo]-2-naphthalenylamine (or Red tofat 7B) and those wherein the azodyestuff isN,N-diethyl-4-(phenylazo)-benzeneamine (Yellow to fat GGN). Among thepreferred light-stable compositions of the invention are compositionscontaining compounds of formula I wherein R is ##STR9## and especiallyα-cyano -3-phenoxy-benzyl or α-ethynyl-3-phenoxy-benzyl or3-phenoxy-benzyl

The most preferred compositions of the invention are those containing asthe active ingredient an ester selected from the group consisting of(S)α-cyano-3-phenoxy-benzyl (1R, cis)2,2-dimethyl-3-(2,2-dibromovinyl)-cyclopropane-1-carboxylate,(S)α-cyano-3-phenoxy-benzyl (1R, cis)2,2-dimethyl-3-(2,2-dichloro-1,2-dibromo-ethyl)-cyclopropane-1-carboxylate,(S)α-cyano-3-phenoxy-benzyl (1R, trans)2,2-dimethyl-3-(2,2-dichloro-1,2-dibromo-ethyl)-cyclopropane-1-carboxylateand (S)α-cyano-3-phenoxy-benzyl (1R, cis)2,2-dimethyl-3-(1,2,2,2,-tetrabromo -ethyl)-cyclopropane-1-carboxylate.

The compositions preferably contain 5 to 100 g per liter of at least oneactive compound of formula I and 0.1 to 10 g per liter of at least oneazodyestuff stabilizer. The liquid vehicle may be of a wide variety ofliquids and a preferred group of liquids are aromatic hydrocarbons suchas xylene or toluene.

The surface active agents may also be of a wide variety. Examples ofpreferred surface active agents are members of the group consisting ofpolyoxyethylene polymethylsiloxane, polyethylenepolyoxypropylenepolymethylsiloxane, monolaurate of sorbitol anhydrous oxyethylene,monooleate of sorbitol anhydrous oxyethylene, tridecylalcoholoxyethylene, nonylphenol oxyethylene, polyglycolic ethers of fattyalcohols, tributylphenylpolyglycolic ethers, calcium salts ofalkylsulfonic acids and aryl sulfonic acids, phosphoric esters,alkylamino polycarboxylic acid derivatives, alkali metal salts ofpolyvalent amines, salts of organic carboxylic acids and organosulfonicacids, lignosulfonates, N-sulfo or N-phosphosuccinates of esters ofα-amino acids, sodium alkyl naphthalene sulfonates, condensationproducts of aminosulfonic acids or aminocarboxylic acids with alkylhaloacetic acids and polyglycerol oleates. The compositions preferablycontain 1 to 100 g/liter of surface active agent.

The degree of protection of the pyrethrinoids from light is evidentiallynot identical with all the surface active agents used in the case thatall other factors are the same. It is especially noted that theassociation of the surface active agent with the azodyestuffs results ingood protective results. Especially preferred surface active agents arephosphoric acid esters and polyglycerol oleates.

In a preferred modification of the invention, the compositions alsocontain a component capable of fixing the mixture of the invention tothe vegetable leaves such as ethylcellulose.

The process of the invention for the stabilization of pesticidalcompositions comprises incorporating into a mixture of at least onecompound formula I in at least one liquid vehicle an effective amount ofat least one surface active agent soluble in the liquid vehicle and atleast one of the azodyestuffs recited above. Preferably, thecompositions contain 5 to 100 g per liter of the pyrethrinoids offormula I and 0.1 to 10 g per liter of the azodyestuff stabilizer.

It is perceived that the emulsifiable concentrates containing thepyrethrinoids as the active ingredient see the latter being degraded bylight in such a manner that practical use of these compositions canbecome impossible. Due to the stabilized compositions of the invention,compositions which are in the form of an emulsifiable concentrate andwhich contain azedyestuffs, diverse classes of pyrethrinoids enumeratedabove as formula I have increased stability as demonstrated in theexamples infra.

The stabilized compositions of the invention are capable of being usedin agriculture, especially in open fields without loss of activity andunder the most economical conditions. The same compounds not stabilizedwith azodyestuffs are usually degraded to a such a large extent by theaction of light so that their use is not economical. Due to the intenseinsecticidal activity of the pyrethrinoids of formula I, the inventionassumes a great practical importance.

The method of the invention for combatting pests comprises contactingthe pests with a pesticidal amount of a composition of the invention.The usual useful dose as an agricultural insecticide is 1 to 100 g perhectare.

Referring now to the FIGS.:

The figures are graphs of the insecticidal activity of the examples andclearly show the very important stabilization to the light due to theuse of the azodyestuffs.

In the following examples there are described several preferredembodiments to illustrate the invention. However, it should beunderstood that the invention is not intended to be limited to thespecific embodiments.

EXAMPLE 1

A stabilized composition was prepared consisting of 25 g of(S)α-cyano-3-phenoxy-benzyl (1R, cis)2,2-dimethyl-3-(2,2-dibromovinyl)-cyclopropane-1-carboxylate, 70 g ofnon-ionic monolaurate of anhydrous sorbitol oxyethylene, 23 g of anionicsodium alkylnaphthalene sulfonate, 15 g of ethyl cellulose, 1 g ofN,N-diethyl-4-(phenylazo)-benzeneamine (Yellow to fat GGN) andsufficient xylene for a total volume of one liter.

EXAMPLE 2

A stabilized composition was prepared consisting of 20 g of(S)α-cyano-3-phenoxy-benzyl (1R, trans) 2,2-dimethyl-3-(2,2-dichloro-1,2-dibromoethyl)-cyclopropane-1-carboxylate, 75 g ofoxyethylene nonylphenol, 18 g of anionic lignosulfonate, 8 g ofethylcellulose, 1 g of N-ethyl-1-[{4-(phenylazo)-phenyl}-azo]-2-naphthalenylamine (Red to fat 7B) and sufficient toluenefor a final volume of one liter.

STABILITY TEST

To determine the stability as a function of time, emulsifiableconcentrates were prepared containing 25 g of the test pyrethrinoidcompound, 82 g of a non-ionic oxyethylenated product of a mixture ofaliphatic alcohols of 12 to 13 carbon atoms, 18 g of anionic calciumphenylsulfonate, 10 g of ethylcellulose, 1 g of azodyestuff andsufficient xylene for a final volume of one liter. The test compounds offormula I used were (S)α-cyano-3-phenoxy-benzyl (1R, cis) 2,2-dimethyl-3-(2,2-dibromovinyl)-cyclopropane--carboxylate [compound A],(S)α-cyano-3-phenoxy-benzyl (1R, cis) 2,2-dimethyl-3-(2,2-dichloro-1,2-dibromoethyl)-cyclopropane-1-carboxylate [compound B],(S)α-cyano-3-phenoxy-benzyl (1R, trans) 2,2-dimethyl-3-(2,2-dichloro-1,2-dibromoethyl)-cyclopropane-1-carboxylate [compoundC] and (S)α-cyano-3-phenoxy-benzyl (1R, cis) 2,2-dimethyl-3-(1,2,2,2-tetrabromoethyl)-cyclopropane-1-carboxylate[compound D].

The test procedure involved measuring the kinetics of degradation underan overhead light by placing 200 μl of emulsifiable concentratecontaining the active ingredient at a dose of 25 g/l (or 5 mg) in abeaker of 25 ml with a diameter of 30 mm so as to spread the deposit inthe form of a ring on the bottom of the beaker. The test thus avoidssurface irregularities in irradiation of the different samples. Theorganic solvent in the formulation was then removed by a current of hotair over about 20 minutes and the resulting beakers were then placedunder an overhead light source (one hour of exposition at 150 klux=to 14hours of average daylight) and held there for the indicated time. Afterlight irradiation, the contents of the beaker were taken up in 1 to 2 mlof methylene chloride and the amount of the pyrethrinoid compounds wasdetermined by high pressure liquid chromatography.

The mixtures of the test compound and azodyestuff used were (1) amixture of compound A and N-ethyl-1-[{4-phenylazo)-phenyl}-azo]-2-naphthalenylamine (Red to fat 7B), (2) a mixture ofcompound A and N,N-diethyl-4-(phenylazo)-benzeneamine (Yellow to fatGGN), (3) a mixture of compound B and red to fat 7B, (4) a mixture ofcompound B and Yellow to fat GGN, (5) a mixture of compound B and Ruby R(mixture of 1-[{-4- (phenylazo)-phenyl}-azo]-3-naphthalenol and4-[{-4-(phenylazo)- phenyl}-azo-phenol, (6) a mixture of compound C andred to fat 7B, (7) a mixture of compound C and red to fat GGN, (8) amixture of compound C and Scarlet R, (9) a mixture of compound D andliquid red to fat 7B (a 65% solution of red to fat 7B in an aromaticsolvent), (10) a mixture of compound D and blue to fat B orN-[4-(phenyl-{4-phenylamino}-1-naphthalenyl)-methylene]-2,5-cyclohexadien-1-ylidene-N-methyl-methaniminium chloride,(11) a mixture of compound D and liquid yellow to fat G (a liquid dyewho structure is not indicated in Color Index), (12) a mixture ofcompound D and yellow to fat GGN, (13) a mixture of compound D andyellow to fat 3G or 2,4-dihydro-5-methyl-2phenyl-4-phenylazo-3H-pyrazol-3-one, (14) a mixture ofcompound D and black to fat HB or 2,3-dihydro-2,2-dimethyl-6-[(4-phenylazo)-1-naphthalenyl]-azo-1H-perimidine, (15) amixture of compound D powdered red to fat 7B, (16) a mixture of compoundD and Scarlet R, (17) a mixture of compound D and red organol BS, (18) amixture of compound D and red Sudan IV, (19) a mixture of compound D andvermillon organol, (20) a mixture of compound D and red to fat G, (21) amixture of compound D and azo ruby, (22) a mixture of compound D and amixture of 1/3 brown to fat B, 1/3 brown to fat RR and 1/3 Ruby RR tofat, (23) a mixture of compound D and brown to fat B, (24) a mixture ofcompound D and red to fat 5B, (25) a mixture of compound D and red tofat 7B, (26) a mixture of compound D and brown to fat RR, (27) a mixtureof compound D and Red Sudan I, (28) a mixture of compound D and redSudan II and (29) a mixture of compound D and 1-[{4-(phenylazo)-phenyl}-azo-]2-naphthalenol.

The results of the tests are expressed in the Figures submitted herewithwherein the percentage of degradation is plotted as a function of time.The tests were effected in comparison with a non-stabilized emulsifiableconcentrate indicated as standard emulsifiable concentrate which wasidentical to the test compositions except for the presence of theazodyestuff.

Various modifications of the compositions and method of the inventionmay be made without departing from the spirit or scope thereof and it isto be understood that the invention is intended to be limited only asdefined in the appended claims.

What is claimed is:
 1. A light stable pyrethrinoid compositioncomprising (a) at least one liquid vehicle, (b) at least onesurface-active agent soluble in the said liquid vehicle, (c) at leastone azodyestuff stabilizer selected from the group consisting of amixture of 1-[{4-(phenylazo)-phenyl)}- azo]-3-naphthalenol and4-[{4-(phenylazo)-phenyl}-azo]-phenol (a component of Scarlet R),1-[4-(4-phenylazo-phenyl)-azo]- naphthalene (Red organol BS),1-[{2-methyl-4-(2-methylphenylazo)-phenyl}-azo]-2-naphthalenol (RedSudan IV), 1-[(1-naphthalenyl)-azo]-2-naphthalenol (Scarlet 2R for fat),1-(phenylazo)-2-naphthalenol (Sudan I),1-[(2-hydroxy-4-methyl-phenyl)-azo]-2-naphthalenol (Sudan II),1-[{dimethyl-4-[(dimethyl-phenyl)-azo}-phenylazo]-2-naphthalenol (Red tofat 5B), 2-[(2-methoxypheny)-azo]-phenol (Red to fat G),4-[(4-ethoxyphenyl)-azo]-1-naphthalenol (Brown to fat B), and1-[{4-(phenylazo)-phenyl}-azo]-2-naphthalenol and (d) at least one esterof the formula ##STR10## wherein Y is selected from the group consistingof ##STR11## in its various stereoisomeric forms and mixtures thereof, Zis alkyl of 1 to 6 carbon atoms, Y is selected from the group consistingof hydrogen, halogen, --CN, --NO₃, alkyl of 1 to 4 carbon atoms andalkoxy of 1 to 4 carbon atoms, n is 0,1,2 or 3, W is selected from thegroup consisting of ##STR12## X₁ is selected from the group consistingof hydrogen, fluorine, chlorine and bromine, X₂ is selected from thegroup consisting of fluorine, chlorine and bromine, X₃ is selected fromthe group consisting of chlorine, bromine and iodine, X₄ is a halogenand X₅ is a halogen optionally other than that of X₄ and due toasymetric carbon atom in W, the compounds are in the A isomer or Bisomer form or mixtures thereof and R is selected from the groupconsisting of ##STR13## and benzyl optionally substitued with at leastone member of the group consisting of alkyl of 1 to 4 carbon atoms,alkenyl of 2 to 6 carbon atoms, alkenyloxy of 2 to 6 carbon atoms,alkadienyl of 4 to 8 carbon atoms, methylenedioxy, benzyl and halogens,R₁ is selected from the group consisting of hydrogen and methyl, R₂ isselected from the group consisting of monocyclic aryl and --CH₂--C.tbd.CH, R₃ is an aliphatic of 2 to 6 carbon atoms having at leastone carbon-carbon insaturation, R₄ is selected from the group consistingof hydrogen, --CN, CH₃ and --C.tbd.CH, R₅ is selected from the groupconsisting of chlorine and methyl, n is 0, 1 or 2, R₆, R₇, R₈ and R₉ areindividually selected from the group consisting of hydrogen, chlorineand methyl and S/I indicates that the ring may be aromatic, dihydro ortetrahydro the alcoholic moiety R--OH being capable of containing one ormore asymetric carbon atoms and of existing in the form of variousstereoisomers.
 2. A composition of claim 1 in the form of anemulsifiable concentrate.
 3. A composition of claim 1 wherein theazodyestuff is 1-[{4-(phenylazo)-phenyl}-azo]-2-naphthalenol.
 4. Acomposition of claim 1 wherein the azodyestuff is a mixture of1-[{4-(phenylazo)-phenyl}-azo]-3-naphthalenol and4-[{4-(phenylazo)-phenyl}-azo]-phenol.
 5. A composition of claim 1wherein R is ##STR14##
 6. A composition of claim 5 wherein R is selectedfrom the group consisting of 3-phenoxy-benzyl, α-cyano-3- phenoxy-benzyland α-ethynyl-3-phenoxy-benzyl.
 7. A composition of claim 1 wherein thepyrethrinoid is (S)α-cyano-3-phenoxy-benzyl (1R, cis)2,2-dimethyl-3-(2,2- dibromovinyl)-cyclopropane-1-carboxylate.
 8. Acomposition of claim 1 wherein the pyrethrinoid is(S)α-cyano-3-phenoxy-benzyl (1R, cis)2,2-dimethyl-3-(2,2-dichloro-1,2-dibromoethyl)-cyclopropane-1-carboxylate.9. A composition of claim 1 wherein the pyrethrinoid is(S)α-cyano-3-phenoxy-benzyl (1R, trans)2,2-dimethyl-3-(2,2-dichloro-1,2-dibromoethyl)-cyclopropane-1-carboxylate.10. A composition of claim 1 wherein the pyrethrinoid is(S)α-cyano-3-phenoxy-benzyl (1R, cis) 2,2-dimethyl-3-(1,2,2,2-tetrabromoethyl)-cyclopropane-1-carboxylate.
 11. A composition ofclaim 1 containing 5 to 100 g per liter of the pyrethrinoid and 0.1 to10 g per liter of azodyestuff.
 12. A composition of claim 1 wherein thesurface active agent is selected from the group consisting ofpolyoxyethylene polymethylsiloxane, polyethylenepolyoxpropylene,polymethylsiloxane, monolaurate of sorbitol anhydrous oxyethylene,monooleate of sorbitol anhydrous oxyethylene, tridecyl alcoholoxyethylene, nonylphenol oxyethylene, polyglycolic ethers of fattyalcohols, tributylphenylpolyglycolic ethers, calcium salts of alkylsulfonic acids and aryl sulfonic acids, phosphoric esters, alkylaminopolycarboxylic acid derivatives, alkali metal salts of polyvalentamines, or organic carboxylic acids and organosulfonic acids,lignosulfonates, N-sulfo or N-phosphosuccinates of esters of aminoacids, sodium alkylnaphthelene sulfonates, condensation products ofaminosulfonic acids or aminocarboxylic acids with alkylhaloacetic acidsand polyglycerol oleates.
 13. A composition of claim 12 wherein thesurface active agent is selected from the group consisting of oleates ofpolyglycerol and phosphoric acid esters.
 14. A method of combattingpests comprising contacting pests with a pesticidal amount of acomposition of claim
 1. 15. A method of claim 14 wherein the compositionis in the form of an emulsifiable concentrate.
 16. A method of claim 14wherein the azodyestuff is1-[{4-(phenylazo)-phenyl}-azo]-2-naphthalenol.
 17. A method of claim 14wherein the azodyestuff is a mixture of1-[{4-(phenylazo)-phenyl}-azo]-3-naphthalenol and4-[{4-(phenylazo)-phenyl}-azo]-phenol.
 18. A method of claim 14 whereinR is ##STR15##
 19. A method of claim 14 wherein R is selected from thegroup consisting of 3-phenoxy-benzyl, α-cyano-3-phenoxy-benzyl andα-ethynyl3-phenoxy benzyl.
 20. A method of claim 14 wherein thepyrethrinoid is (S)α-cyano-3-phenoxy-benzyl (1R, cis)2,2-dimethyl-3-(2,2- dibromovinyl)-cyclopropane-1-carboxylate.
 21. Amethod of claim 14 wherein the pyrethrinoid is(S)α-cyano-3-phenoxy-benzyl (1R, cis) 2,2-dimethyl-3-(2,2-dichloro-1,2-dibromoethyl)-cyclopropane-carboxylate.
 22. A method ofclaim 14 wherein the pyrethrinoid is (S)α-cyano-3-phenoxy-benzyl (1R,trans) 2,2-dimethyl-3-(2,2-dichloro-1,2-dibromoethyl)-cyclopropane-1-carboxylate.
 23. A method ofclaim 14 wherein the pyrethrinoid is (S)α-cyano-3-phenoxy-benzyl (1R,cis) 2,2-dimethyl-3-(1,2,2,2,-tetrabromoethyl)-cyclopropane-1-carboxylate.
 24. A method of claim 14containing 5 to 100 g per liter of the pyrethrinoid and 0.1 to 10 g perliter of azodyestuff.
 25. A method of claim 16 wherein the surfaceactive agent is selected from the group consisting of polyoxyethylenepolymethylsiloxane, polyethylenepolyoxypropylene polymethyl silioxane,monolaurate of sorbitol anhydrous oxyethylene, monooleate of sorbitolanhydrous oxyethylene, tridecyl alcohol oxyethylene, nonylphenoloxyethylene, polyglycolic ether of fatty alcohols,tributylphenylpolycolic ethers, calcium salts of alkylsulfonic acids andarylsulfonic acids, phosphoric esters, alkylamines polycarboxylic acid,derivatives, alkali metal salts of polyvalent amines of organiccarboxylic acids and organosulfonic acids, lignosulfonates, N-sulfo- orN-phosphosuccinates of esters of amino acids, sodium alkyl naphalenesulfonates, condensation products of aminosulfonic acids oraminocarboxylic acids with alkylhaloacetic acids and polyglycerololeates.
 26. A method of claim 14 wherein the surface active agent isselected from the group consisting of oleates of polyglycerol andphosphoric acid esters.
 27. A process for stabilizing a liquidcomposition containing a light sensitive pyrethrinoid compound of claim1 comprising incorporating therein at least one surface active agentsoluble in the liquid media and at least one azodyestuff of claim
 1. 28.A process of claim 27 wherein the composition contains 5 to 100 g perliter of the pyrethrinoid compound and 0.1 to 10 g per liter of theazodyestuff and 1 to 100 g/liter of surface active agent.
 29. A processof claim 27 wherein the azodyestuff is1-[{4-(phenylazo)-phenyl}-azo]-2-naphthalenol.
 30. A process of claim 27wherein the azodyestuff is a mixture of1-[{4-(phenylazo)-phenyl}-azo]-3-naphthalenol and4-[4-(phenylazo)-phenyl -azol]-phenol.